Endodontic therapy consists of filing and shaping the canal with instruments such as files, reamers, etc. This process produces shavings and debris made up of dentin and soft tissue (vein, nerve and capillary which makes up "pulp"). To prevent compacting and clogging of the canal with debris, it is necessary to irrigate the canal to keep it clean.
Traditionally the irrigation is done with a rigid irrigator tip made of metal, such as a hypodermic needle in various diameters. The problem with this is that the rigid metal or plastic tubes cannot negotiate to the end of the canal especially if the canal is curved. Also, the rigid metal end/plastic end has an edge which serves to bind the canal walls which can gouge and prevent adequate access. Another problem is that the opening at the end directs the pressure outward toward the apex of the root which can send debris and or irrigation fluid beyond the apex and into soft tissues causing medical complications.
Outside of the medical and dental field, flexible silicone needles of Technitool Company include hollow, flexible silicone needles for dispensing lubricating fluids to computer components.
Moreover, various attempts have been made to provide flexible fluid delivery conduits with discharge ports in the medical and dental field. Among these devices include U.S. Pat. No. 5,127,831 of Bab for a dental irrigation probe having a flexible tube attached to a rigid curved handle for forcibly delivering fluid between the outer periodontal surfaces of teeth, not within definitive body cavities, such as canals within the teeth. In Bab '831 the fluid is directed out axially through the probe.
U.S. Pat. No. 4,512,769 of Kozam describes a flexible needle having a single axially aligned fluid discharge port for cleaning between the teeth not necessarily within a definitive body cavity, such as a tooth canal. It includes a semi-rigid conical nozzle member at the fluid discharge end.
U.S. Pat. No. 4,702,260 of Wang describes a flexible bronchoscopic needle for retrieval of body tissues and body fluids therethrough. It includes a rigid needle attached to a flexible conduit. However, it is used to retrieve bodily fluids, and tissues, not to irrigate or provide medicine to a definitive body cavity, such as a tooth canal.
U.S. Pat. No. 4,735,619 of Sperry describes a rigid needle attached to a flexible conduit for intravenous introduction of fluids to the body. Since, the needle is not flexible, it may lodge against the walls of a tooth canal and break it, and it can't negotiated curved canals.
U.S. Pat. No. 4,274,555 of Sneider describes a feminine douche applicator with a hollow nozzle having lateral side ports for delivery of fluid therefrom. However, the applicator in Sneider is not on a scale of size for use within a tooth canal.
U.S. Pat. No. 3,884,230 of Wulff a flexible needle aiming device comprising a rigid needle within a helical spring member for aiming the needle properly to an injection site upon the skin of a recipient of fluids therefrom. However, Wolff '230 is inflexible and can't negotiate curved tooth canals.
Furthermore, U.S. Pat. No. 4,026,025 of Hunt descibes an air powered fluid delivery nozzle for thrusting a fluid and air mix or just air forcefully therefrom into the intraoral mouth cavity of a dental patient. In Hunt '025 the nozzle is inflexible and the fluid is directed out axially through the nozzle. The nozzle is not on a scale of size for use within a tooth canal.
Therefore, the aforementioned prior art devices are not suitable for intra-canal irrigation of a tooth during endodontic treatment.